When to Plant Chervil in Greene County, IL
Chervil is a delicate herb with a subtle anise-parsley flavor, essential in French cuisine as part of fines herbes. It prefers cool conditions and partial shade.
Greene County, Illinois is in USDA Zone 5b. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.
At an elevation of 1,248 feet, Greene County receives approximately 37 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Chervil during the growing season.
Greene County Soil Profile
Soil Type
Silt Loam
Soil pH
6.1-6.7
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Greene County
How your county's soil matches Chervil's growing requirements.
Soil pH
Your soil pH (6.1–6.7) is within Chervil's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Greene County is excellent for Chervil — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Chervil.
Organic Matter
Organic matter is excellent (4.5%) — Chervil will thrive.
How to Plant Chervil
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Chervil
Sow every 4.6 weeks. Last sowing by Aug 22 to harvest before frost.
For a dedicated fall crop, sow by Aug 12.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Chervil
Chervil needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Chervil Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.7" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Greene County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Chervil Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Chervil Planting Timeline — Greene County, IL
Chervil Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 9 | Mar 9 – Mar 23 |
| Transplant Outdoors | April 6 | Apr 6 – Apr 20 |
| Direct Sow | March 30 | Mar 30 – Apr 20 |
| Harvest | May 18 | May 18 – Jul 20 |
| Fall Sowing | August 12 | Aug 12 – Aug 26 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
40–60 days
🧪 Soil pH
Needs 6–7 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
191 days in Greene County
Growing Tips for Chervil in Greene County
Direct sow Chervil outdoors after April 13 in Greene County when soil has warmed and frost danger has passed.
Your generous 191.0-day season in Greene County allows multiple plantings of Chervil. Sow every 20.0 days for continuous harvest.
Common pests for Chervil in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow in early spring or fall as chervil bolts in heat. Provide shade and cool conditions. Harvest outer leaves as needed; use fresh as it loses flavor when dried.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Chervil in Other Locations
Frequently Asked Questions
When should I plant Chervil in Greene County, IL?
Greene County is in Zone 5b with an average last frost of April 13. Plan your Chervil planting based on this frost date — see the calendar above for exact timing.
What planting zone is Greene County, IL?
Greene County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 13 and first fall frost is October 21.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Greene County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.